Vehicle Control Systems

Abstract

To prevent a second control device from being brought into a wake-up state when an ignition switch is in an OFF-state, so that consumption currents do not increase, when the second control device also utilizes detected data by an acceleration detecting part provided in a first control device.SOLUTION: Pieces of detected acceleration data detected by an acceleration sensor 21 of an ECU 2 for controlling an airbag just after a vehicle stops while an ignition switch is in an OFF-state are memorized in a memory 23, and pieces of detected acceleration data detected just before the ignition switch is turned off memorized in the memory 23 are transmitted from a transmission part 24 of the ECU 2 for controlling an airbag just after the ignition switch is turned on, and the pieces of data are received by a reception part 31 of an ECU 3 for controlling an optical axis to derive a vehicle attitude angle θv, so as to control an inclination angle of an optical axis of a head lamp.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vehicle control system that controls a vehicle based on data detected by an acceleration sensor. [Background technology]

[0002] Conventionally, there has been a so-called auto-leveling control device that controls the tilt angle of the optical axis of the headlamp as a device that controls a vehicle based on detection data from an acceleration sensor. This type of device detects the vehicle attitude angle and controls the optical axis of the headlamp according to the detected vehicle attitude angle to perform auto-leveling control to prevent dazzling to oncoming vehicles, and one such device is described in Patent Document 1, for example.

[0003] The auto-leveling control device described in Patent Document 1 uses an inclination sensor consisting of a three-axis acceleration sensor to detect acceleration in three directions (up / down, front / rear, and left / right) of the vehicle, and derives a road surface inclination angle θr, which is the angle in the vehicle's pitch direction, and a composite angle θ of the vehicle attitude angle θv from the data detected by this inclination sensor. Because the vehicle attitude angle θv rarely changes while the vehicle is traveling due to changes in the load or number of occupants, a change in the composite angle θ while the vehicle is traveling is determined to be a change in the road surface inclination angle θr. However, because the road surface inclination angle θr does not change while the vehicle is stopped, a change in the composite angle θ while the vehicle is stopped is determined to be a change in the vehicle attitude angle θv, and the headlamp beam axis is controlled in response to the change in the vehicle attitude angle θv while the vehicle is stopped due to the ignition switch being turned off.

[0004] In the case of a device such as that described in Patent Document 1, the acceleration detected by the tilt sensor is used not only for auto-leveling control, but also for various other controls such as vehicle airbag control and skid prevention control while driving. Therefore, in order to prevent cost waste caused by providing dedicated tilt sensors for each of these various controls, it has been considered to share one tilt sensor for each of these various controls in order to reduce costs.

[0005] At this time, acceleration detection data from an inclination sensor mounted on an ECU (Electronic Control Unit) constituting an airbag control device is transmitted via CAN (Controller Area Network) communication, and the data is received by the auto-leveling control ECU, which calculates the vehicle attitude angle based on the received acceleration detection data, and controls the tilt angle of the headlamp optical axis according to the calculated vehicle attitude angle. to Not only this, but also the ECU for the side slip suppression control is also connected by CAN communication. Rie The system receives acceleration detection data sent from the ATV control ECU and performs various controls. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-98297 Summary of the Invention [Problem to be solved by the invention]

[0007] However, when acceleration detection data from a single shared incline sensor is sent and received via CAN communication, particularly in cases such as auto-leveling control, where the vehicle sways when the ignition switch is off due to passengers getting in and out or luggage being loaded and unloaded, it is necessary to send and receive acceleration detection data from the shared incline sensor even when the ignition switch is off.When the ignition switch is turned off, all control ECUs should go into a sleep state to reduce current consumption, but when acceleration detection data is sent via CAN communication while the ignition switch is off, a specific ECU that receives this data and performs control goes into a wake-up state, resulting in increased current consumption and potentially draining the battery.

[0008] Furthermore, even if the acceleration detection data from an incline sensor installed in an ECU for a specified control is sent to an ECU for auto-leveling control via communication other than CAN communication, not only the ECU equipped with the incline sensor but also the ECU for auto-leveling control must be kept in a wake-up state, which still results in an increase in current consumption.

[0009] The present invention aims to prevent the second control device from entering a wake-up state when the ignition switch is turned off, resulting in an increase in current consumption, when the detection data of an acceleration detection unit provided in a first control device is also used in a second control device. [Means for solving the problem]

[0010] In order to achieve the above object, a vehicle control system of the present invention is a vehicle control system that controls a vehicle based on detection data from an acceleration sensor, and includes a first control device that controls the vehicle, and a second control device that performs predetermined control of the vehicle different from the control performed by the first control device, and the first control device includes an acceleration detection unit that detects acceleration in at least the vertical direction and the longitudinal direction in order to derive a road surface inclination angle and a vehicle attitude angle. ,car Both cars stopped. When the vehicle is judged to be stable, The acceleration detection unit Add a storage unit that stores speed detection data; and a transmission unit that transmits the acceleration detection data stored in the storage unit immediately after an ignition switch is turned on and transmits the acceleration detection data detected by the acceleration detection unit while the ignition switch is on, When the ignition switch is turned off, if the acceleration detection data has been stored in the storage unit, the device goes into a sleep state, The second control device includes a receiving unit that receives the acceleration detection data stored in the storage unit and transmitted from the transmitting unit immediately after the ignition switch is turned on, and receives the acceleration detection data transmitted from the transmitting unit while the ignition switch is turned on. While the ignition switch is off, the acceleration detection data is not transmitted from the transmitter. It is characterized by the following.

[0011] According to this configuration, in the first control device ,car Both cars stopped. When the vehicle is judged to be stable,Acceleration detection data from the acceleration detection unit is stored in a storage unit, and immediately after the ignition switch is turned on, the receiving unit of the second control unit receives the acceleration detection data stored in the storage unit that is transmitted from the transmitting unit of the first control unit. In this way, if the acceleration detection data has been stored in the memory unit when the ignition switch is turned off, the first control device goes into a sleep state, and the second control device does not transmit the acceleration detection data from the transmitter while the ignition switch is turned off. Therefore, when the ignition switch is turned off, the second control device can be prevented from entering a wake-up state to receive acceleration detection data, and an increase in current consumption due to the second control device waking up can be prevented.

[0012] In addition, the device may be provided with a plurality of the first control devices, each of which performs a different control different from the predetermined control, and the receiving unit of the second control device may selectively receive the acceleration detection data transmitted from the transmitting units of the plurality of first control devices.

[0013] As a result, the receiving unit of the second control device selectively receives one of the acceleration detection data from the acceleration detection units of the multiple first control devices, so even if there are multiple first control devices equipped with acceleration detection units, it is possible to prevent the second control device from entering a wake-up state to receive acceleration detection data when the ignition switch is turned off, and to prevent an increase in current consumption due to the second control device waking up.

[0014] The second control device may further include a calculation unit that calculates the vehicle attitude angle based on the acceleration detection data received by the receiving unit when the ignition switch is turned on, and a light axis control unit that controls a tilt angle of the light axis of a headlamp based on the vehicle attitude angle calculated by the calculation unit.

[0015] As a result, in the first control device, when the ignition switch is turned off, the receiving unit of the second control device receives the acceleration detection data transmitted from the transmitting unit of the first control device, the calculating unit calculates the vehicle attitude angle based on the received acceleration detection data, and the optical axis control unit controls the tilt angle of the headlamp optical axis based on the calculated vehicle attitude angle, so that the tilt angle of the headlamp optical axis can be controlled while preventing the second control device from entering a wake-up state to receive acceleration detection data when the ignition switch is turned off. [Effects of the Invention]

[0016] According to this invention, when the detection data of the acceleration detection unit provided in the first control device is also used in the second control device, it is possible to prevent the second control device from going into a wake-up state when the ignition switch is turned off, and the increase in current consumption due to the wake-up can be prevented, which reduces the battery but It is possible to prevent wear. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a block diagram of a first embodiment of a vehicle control system according to the present invention; [Figure 2] 2 is a flowchart illustrating the operation of FIG. 1. [Figure 3] 2 is a flowchart illustrating the operation of FIG. 1. [Figure 4] 10 is a flowchart illustrating the operation of the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0018] (First embodiment) A first embodiment of a vehicle control system according to the present invention will be described in detail with reference to FIGS.

[0019] As shown in FIG. 1, the vehicle control system 1 includes an airbag control ECU 2 that is powered by a battery, is triggered to operate when the ignition switch is turned on, and controls the deployment of airbags in the driver's seat and passenger seat, an optical axis control ECU 3 that is powered by a battery, is triggered to operate when the ignition switch is turned on, and controls the tilt angle of the optical axis of a headlamp (not shown) (auto-leveling control), and a communication bus 4 for CAN communication.

[0020] The airbag control ECU 2 includes a three-axis acceleration sensor 21, which is an acceleration detection unit that detects acceleration in three axial directions, i.e., up-down, front-rear, and left-right, of the vehicle, an airbag control unit 22 that determines whether or not an airbag should be deployed to protect the occupant in a vehicle collision based on acceleration detection data from the acceleration sensor 21 and controls the deployment of the airbag when it is determined that an airbag should be deployed, a memory 23 that is a storage unit that stores the acceleration detection data from the acceleration sensor 21 and data necessary for controlling the airbag control unit 22, and a transmission unit 24 that transmits predetermined data via the CAN communication bus 4 under the control of the airbag control unit 22. Here, the acceleration sensor 21 needs to be capable of detecting acceleration in at least two axial directions, i.e., up-down and front-rear.

[0021] Here, airbag control unit 22 stores in memory 23 acceleration detection data detected by acceleration sensor 21 immediately after the vehicle has stopped, including while the ignition switch is off, and controls transmission unit 24 immediately after the ignition switch is turned on to transmit the acceleration detection data stored in memory 23 immediately after the vehicle has stopped, including while the ignition switch is off, to communication bus 4. While the ignition switch is on, transmission unit 24 transmits data necessary for vehicle control, such as data related to the deployment state of the airbag, in addition to the acceleration detection data detected by acceleration sensor 21, to communication bus 4 at the communication cycle of CAN communication.

[0022] The optical axis control ECU 3 includes a receiver 31 that receives acceleration detection data, which is data stored in the memory 23 immediately after the vehicle is stopped including when the ignition switch is off, transmitted from the transmitter 24 of the airbag control ECU 2 immediately after the ignition switch is turned on, and receives the acceleration detection data transmitted from the transmitter 24 at the CAN communication cycle while the ignition switch is on. The receiver 31 calculates the vehicle attitude angle θv based on the acceleration detection data received by the receiver 31. Played a light axis control unit 33 that controls the angle of the light axis of the headlamp based on the vehicle attitude angle θv calculated by the calculation unit 32; and a memory 34 that stores data necessary for the calculation by the calculation unit 32, data necessary for the light axis control, etc.

[0023] Incidentally, when acceleration detection data by the acceleration sensor 21 is transmitted from the transmitter 24, it is received by the receiver 31 via the communication bus 4. From the angle formed by the resultant vector of the acceleration vectors in the vehicle's longitudinal direction and the acceleration vectors in the vehicle's vertical direction among the received acceleration detection data, the composite angle θ of the road surface inclination angle θr in the vehicle's pitch direction and the vehicle attitude angle θv is derived. At this time, since the load and the number of occupants do not change while the vehicle is traveling, the vehicle attitude angle θv does not change, and a change in the composite angle θ while the vehicle is traveling can be determined to be a change in the road surface inclination angle θr. On the other hand, since the road surface inclination angle θr does not change while the vehicle is stopped, a change in the composite angle θ while the vehicle is stopped can be determined to be a change in the vehicle attitude angle θv. Therefore, the optical axis controller 33 derives a change in the vehicle attitude angle θv from a change in the composite angle θ calculated by the calculator 32 while the vehicle is stopped, and derives a change in the road surface inclination angle θr from a change in the composite angle θ calculated by the calculator 32 while the vehicle is traveling.

[0024] More specifically, for example, in a vehicle manufacturer's factory, the vehicle is placed on a horizontal plane to set it as a reference state, and acceleration detection data of the acceleration sensor 21 of the airbag control ECU 2 in the reference state is transmitted from the transmitting unit 24. This acceleration detection data is received by the receiving unit 31 of the optical axis control ECU 3, and the inclination angle of the optical axis of the headlamp is controlled to the initial state by the optical axis control unit 33.

[0025] At this time, since the road surface inclination angle θr and the vehicle attitude angle θv in the reference state are both 0°, these are stored in the memory 34 of the light axis control ECU 3 as the road surface inclination angle reference value (θr=0°) and the vehicle attitude angle reference value (θv=0°).

[0026] Then, when the ignition switch is in the on state and the vehicle changes from traveling to stopped, the calculation unit 32 of the optical axis control ECU 3 subtracts the vehicle attitude angle reference value stored in the memory 34 of the optical axis control ECU 3 from the current composite angle θ calculated from the acceleration detection data by the acceleration sensor 21 of the airbag control ECU 2 to derive a road surface inclination angle θr and stores this as a new road surface inclination angle reference value in the memory 34. By repeating this process, the change in the road surface inclination angle θr and the change in the composite angle θ while the vehicle is traveling, which is estimated, are stored and updated as the road surface inclination angle reference value.

[0027] On the other hand, when the ignition switch is turned on and the vehicle is stopped, the calculation unit 32 of the optical axis control ECU 3 subtracts the road surface inclination angle reference value stored in the memory 34 of the optical axis control ECU 3 from the current composite angle θ calculated from the acceleration detection data by the acceleration sensor 21 of the airbag control ECU 2 to derive a vehicle attitude angle θv, which is stored as a new vehicle attitude angle reference value in the memory 34. By repeating this process, the change in the vehicle attitude angle θv and the change in the composite angle θ while the vehicle is traveling, which are estimated, are stored and held as the vehicle attitude angle reference value.

[0028] Furthermore, even if the ignition switch is turned on after being turned off once, while the vehicle is stopped, the calculation unit 32 of the light axis control ECU 3 subtracts the road surface inclination angle reference value stored in the memory 34 of the light axis control ECU 3 from the current composite angle θ calculated from the acceleration detection data by the acceleration sensor 21 of the airbag control ECU 2 to derive the vehicle attitude angle θv, and stores this as a new vehicle attitude angle reference value in the memory 34. This makes it possible to recognize the vehicle attitude angle even if the vehicle inclination changes while the ignition switch is off. However, there are cases where the road surface inclination angle reference value cannot be calculated while the ignition switch is on, such as when the ignition switch is turned off immediately after stopping the vehicle or when the vehicle continues to sway due to factors such as wind or people immediately after stopping the vehicle. In this case, if CAN communication is stopped after the ignition switch is turned off, the road surface inclination angle reference value cannot be calculated, which may result in an inability to control the light axis.

[0029] To address this issue, the present invention performs the control described below.

[0030] As a measure for when the ignition switch is turned off before the road surface inclination angle reference value is calculated, acceleration detection data by the acceleration sensor 21 of the airbag control ECU 2 is stored in the memory 23 immediately after the vehicle stops, regardless of whether the ignition switch is on or off, and then, immediately after the ignition switch is turned on, the acceleration detection data immediately after the vehicle stops, stored in the memory 23, is transmitted from the transmission unit 24. Then, the acceleration detection data transmitted from the transmission unit 24 immediately after the ignition switch is turned on is received by the receiving unit 31 of the light axis control ECU 3, and the vehicle attitude angle θv is derived by subtracting the road surface inclination angle reference value stored in the memory 34 of the light axis control ECU 3 from the composite angle θ calculated from the received acceleration detection data, and the inclination angle of the headlamp optical axis is controlled by the light axis control unit 33 in accordance with the derived vehicle attitude angle θv.

[0031] Therefore, the acceleration detection data by the acceleration sensor 21 of the airbag control ECU 2 immediately after the vehicle has stopped is stored in the memory 23, and the acceleration detection data stored in the memory 23 is transmitted from the transmitter 24 of the airbag control ECU 2 immediately after the ignition switch is turned on. This transmitted data is received by the receiver 31 of the optical axis control ECU 3 to derive the vehicle attitude angle θv. Therefore, when the ignition switch is turned off, the optical axis control ECU 3 does not enter a wake-up state to receive the acceleration detection data, and an increase in current consumption due to the wake-up of the optical axis control ECU 3 is prevented.

[0032] Next, the control procedure for the tilt angle of the optical axis of the headlamp will be described with reference to the flowcharts of FIGS.

[0033] First, the operation of the airbag control ECU 2 when the ignition switch is shifted from on to off will be described with reference to FIG.

[0034] As shown in FIG. 2, when the ignition switch is turned on, the transmitter 24 of the airbag control ECU 2 transmits acceleration detection data detected by the acceleration sensor 21 when the vehicle was last stopped (step S1). Thereafter, it is determined whether the vehicle is stopped or not based on the amount of brake pedal operation, the vehicle speed detected by the vehicle speed sensor, the position of the shift lever, etc. (step S2). If the vehicle is moving and the determination result of step S2 is NO, the process proceeds to step S6, which will be described later. If the vehicle is stopped and the determination result of step S2 is YES, it is determined whether the vehicle is stable or not (step S3). If the determination result is NO, the process proceeds to step S6, which will be described later.

[0035] On the other hand, if the determination result in step S3 is YES, it is determined whether the vehicle is stable while stopped, with no passengers getting on or off or cargo being loaded or unloaded (step S4).If this determination result is NO, the process proceeds to step S6, which will be described later.If the determination result in step S4 is YES, the acceleration detection data from the acceleration sensor 21 while the vehicle is stopped is stored in memory 23 (step S5), and then it is determined whether the ignition switch has been turned off (step S6).

[0036] If the ignition switch remains on and the determination result in step S6 is NO, the current acceleration detection data by the acceleration sensor 21 is transmitted from the transmission unit 24 (step S7). If the ignition switch is turned off and the determination result in step S6 is YES, it is determined whether the acceleration detection data by the acceleration sensor 21 when the vehicle is stopped with the ignition switch off has been stored in the memory 23 (step S8). If the determination result is NO, the process returns to the processing of step S2 described above. If the determination result in step S8 is YES, the power supply to the airbag control ECU 2 is cut off and the airbag control ECU 2 goes into a sleep state (step S9), and the operation of the airbag control ECU 2 when the ignition switch transitions from on to off is terminated.

[0037] Next, the operation of the optical axis control ECU 3 when the ignition switch is shifted from on to off will be described with reference to FIG.

[0038] As shown in FIG. 3, when the ignition switch is turned on, the road surface inclination angle reference value and the vehicle attitude angle reference value are read from the memory 34 (step S21), and it is determined whether the road surface inclination angle reference value is held (step S22). If the determination result in step S22 is YES, the process proceeds to step S26 (described later). If the determination result in step S22 is NO, the acceleration detection data when the vehicle is stopped, transmitted from the transmitter 24 of the airbag control ECU 2, is received by the receiver 31 (step S23). The vehicle attitude angle reference value is subtracted from the composite angle θ (= road surface inclination angle + vehicle attitude angle) calculated based on the received acceleration detection data to derive the road surface inclination angle θr (step S24). The derived road surface inclination angle θr is newly stored in the memory 34 as an updated road surface inclination angle reference value (step S25), and the process then proceeds to step S26.

[0039] Then, in step S26, a determination is made as to whether the vehicle is stopped based on the amount of brake pedal operation, the vehicle speed detected by the vehicle speed sensor, the position of the shift lever, etc. (step S26). If the vehicle is moving and the determination result of step S26 is NO, the process proceeds to step S34, which will be described later. If the vehicle is stopped and the determination result of step S26 is YES, the process proceeds to step S34, which will be described later. If the determination result of step S27 is YES, the process proceeds to step S28, which will be described later, to determine whether the previous determination was made while the vehicle was moving. If the determination result of step S27 is YES, the process proceeds to step S29, which will be described later. If the determination result of step S28 is NO, the process proceeds to step S31, which will be described later.

[0040] In step S29, the vehicle attitude angle reference value is subtracted from the composite angle θ (= road surface inclination angle + vehicle attitude angle) calculated based on the current acceleration detection data received by the receiving unit 31 to derive the road surface inclination angle θr (step S29), and the derived road surface inclination angle θr is stored and updated in the memory 34 as a new road surface inclination angle reference value (step S30), and then the process proceeds to step S34.

[0041] Also, in step S31, the road surface inclination angle reference value is subtracted from the composite angle θ (= road surface inclination angle + vehicle attitude angle) calculated based on the current acceleration detection data received by the receiving unit 31 to derive the vehicle attitude angle θv (step S31), the derived vehicle attitude angle θv is stored and updated in the memory 34 as a new vehicle attitude angle reference value (step S32), the inclination angle of the headlamp optical axis is controlled by the optical axis control unit 33 in accordance with the new vehicle attitude angle reference value (step S33), and then the process proceeds to step S34.

[0042] Then, in step S34, it is determined whether the ignition switch has been turned off (step S34). If the ignition switch remains on and the determination result of step S34 is NO, the process returns to the processing of step S26 described above. If the ignition switch is turned off and the determination result of step S34 is YES, it is determined whether the road surface inclination angle reference value has been updated (step S35). If the road surface inclination angle reference value has been updated and the determination result of step S35 is YES, the road surface inclination angle reference value and the vehicle attitude angle reference value are stored and saved in the memory 34. If the road surface inclination angle reference value has not been updated and the determination result of step S35 is NO, the road surface inclination angle reference value is stored and saved in the memory 34 (step S37). Thereafter, the power supply to the light axis control ECU 3 is cut off and the light axis control ECU 3 enters a sleep state (step S38), and the operation of the light axis control ECU 3 when the ignition switch transitions from on to off is terminated.

[0043] As described above, according to the first embodiment, the acceleration detection data by the acceleration sensor 21 of the airbag control ECU 2 immediately before the ignition switch is turned off is stored in the memory 23, and immediately after the ignition switch is turned on, the acceleration detection data stored in the memory 23 is transmitted from the transmitter 24 of the airbag control ECU 2, and this transmitted data is received by the receiver 31 of the optical axis control ECU 3 to derive the vehicle attitude angle θv. Therefore, it is possible to prevent the optical axis control ECU 3 from entering a wake-up state to receive the acceleration detection data when the ignition switch is turned off, and to prevent an increase in current consumption due to the wake-up of the optical axis control ECU 3 and suppress battery consumption.

[0044] In addition, the acceleration sensor 21 provided in the airbag control ECU 2 is also used for controlling the tilt angle of the headlamp optical axis (auto-leveling control) by the optical axis control ECU 3, so there is no need to provide a dedicated acceleration sensor for auto-leveling control, which reduces costs.

[0045] (Second embodiment) A second embodiment of a vehicle control system according to the present invention will be described with reference to Fig. 4. Since the basic device configuration of the second embodiment is the same as that of the first embodiment described above, the following description will also refer to Fig. 1, and will mainly focus on the differences between the second embodiment and the first embodiment.

[0046] In this embodiment, the operation of the airbag control ECU 2 when the ignition switch is switched from on to off is the same as in the first embodiment, but the operation of the light axis control ECU 3 when the ignition switch is switched from on to off is different from that in the first embodiment.

[0047] Specifically, with the ignition switch in an on state, while the vehicle is stopped, the receiving unit 31 receives acceleration detection data from the acceleration sensor 21 when the vehicle is stopped, which is transmitted from the airbag control ECU 2 just before the ignition switch is turned off, and the calculating unit 32 calculates a composite angle Tθs when the vehicle is stopped based on the acceleration detection data when the vehicle is stopped, and stores the calculated composite angle Tθs in the memory 34. Then, in order to deal with changes in the vehicle attitude angle when the vehicle is stopped due to passengers getting in and out, etc., the current composite angle θs is added to the light axis control angle TθL when the vehicle is stopped and then the composite angle Tθs stored in the memory 34 is subtracted to derive the light axis control angle θL, and the tilt angle of the headlamp's light axis is controlled to the derived light axis control angle θL, while while the vehicle is running, the unchanged light axis control angle TθL when the vehicle is stopped is maintained to control the tilt angle of the headlamp's light axis, and the power to the light axis control ECU 3 is shut off when the ignition switch is turned off.

[0048] Next, the operation of the optical axis control ECU 3 when the ignition switch is shifted from on to off will be described in detail with reference to the flowchart of FIG.

[0049] As shown in FIG. 4, when the ignition switch is turned on, the road surface inclination angle reference value and the vehicle attitude angle reference value are read from the memory 34 (step S41), and it is determined whether or not a composite angle Tθs based on acceleration detection data when the vehicle is stopped is stored in the memory 34 (step S42). If the determination result is YES, the process proceeds to step S45, which will be described later. If the determination result in step S42 is NO, the acceleration detection data when the vehicle is stopped, transmitted from the transmission unit 24 of the airbag control ECU 2, is received by the receiving unit 31 (step S43), and the composite angle Tθs when the vehicle is stopped (= road surface inclination angle when the vehicle is stopped + vehicle attitude angle when the vehicle is stopped) is derived based on the received acceleration detection data (step S44), and then the process proceeds to step S45.

[0050] Then, in step S45, it is determined whether the vehicle is stopped based on the amount of operation of the brake pedal, the vehicle speed detected by the vehicle speed sensor, the position of the shift lever, etc. (step S45). If the vehicle is moving and the determination result of step S456 is NO, the process proceeds to step S52, which will be described later. If the vehicle is stopped and the determination result of step S45 is YES, it is determined whether the vehicle is stable (step S46). If the determination result is NO, the process proceeds to step S52, which will be described later. R The process proceeds to step S52, and if the determination result of step S46 is YES, it is determined whether or not the previous determination was made while the vehicle was moving (step S47). If this determination result is YES, the process proceeds to step S48, which will be described later. If the previous determination was made while the vehicle was stopped and the determination result of step S47 is NO, it may be necessary to control the headlamp beam axis control angle due to changes in the vehicle attitude angle caused by passengers getting in and out of the vehicle, etc., so the process proceeds to step S50, which will be described later.

[0051] In step S48, if the composite angle Tθs when the vehicle is stopped (=road surface inclination angle when the vehicle is stopped+vehicle attitude angle when the vehicle is stopped) is derived based on the acceleration detection data when the vehicle is stopped received by the receiving unit 31 (step S48), and the unchanged headlamp beam axis control angle TθL when the vehicle is stopped is held (step S49), and then the process proceeds to step S52. Note that in step S48, if the composite angle Tθs when the vehicle is stopped determined in step S42 is stored in the memory 34, that composite angle Tθs is used.

[0052] Also, in step S50, the calculation unit 32 calculates the headlamp optical axis control angle θL (=TθL+θs-Tθs) based on the light axis control angle TθL when the vehicle is stopped, the current composite angle θs, and the composite angle Tθs when the vehicle is stopped (step S50), and the light axis control unit 33 controls the tilt angle of the headlamp optical axis to the calculated light axis control angle θL (step S51), and then the process proceeds to step S52.

[0053] Then, in step S52, it is determined whether or not the ignition switch has been turned off (step S52), and if the ignition switch remains on and the determination result of step S52 is NO, the process returns to the processing of step S45 described above, and if the ignition switch is turned off and the determination result of step S52 is YES, it is determined whether or not the composite angle Tθs when the vehicle is stopped has been derived (step S53), and if this determination result is YES, the light axis control angle TθL when the vehicle is stopped and the composite angle Tθs are stored in the memory 34 (step S54), and if the determination result of step S53 is NO, the light axis control angle TθL when the vehicle is stopped is stored in the memory 34 (step S55), thereafter the power to the light axis control ECU 3 is cut off and the light axis control ECU 3 goes into a sleep state (step S56), and the operation of the light axis control ECU 3 when the ignition switch transitions from on to off is terminated.

[0054] Therefore, according to the second embodiment, as in the first embodiment, it is possible to prevent the optical axis control ECU 3 from entering a wake-up state to receive acceleration detection data when the ignition switch is turned off, and it is possible to prevent an increase in current consumption due to the wake-up of the optical axis control ECU 3 and suppress battery consumption.

[0055] The present invention is not limited to the above-described embodiments, and various modifications other than those described above can be made without departing from the spirit of the present invention.

[0056] For example, in the first and second embodiments described above, the acceleration detection data immediately before the ignition switch is turned off is stored in memory 23, and the acceleration detection data is transmitted from transmission unit 24 immediately after the ignition switch is turned on. However, it is also possible to store an average value of the acceleration detection data detected during a predetermined time immediately before the ignition switch is turned off in memory 23, and transmit the average value from transmission unit 24 immediately after the ignition switch is turned on. By transmitting and receiving the average value in this manner, it is possible to improve the accuracy of the tilt angle control (auto-leveling control) of the headlamp optical axis.

[0057] Furthermore, in each of the above-described embodiments, the first control device is described as an airbag control ECU 2 by way of example, but the first control device is not limited to the airbag control ECU 2, and may also be an ECU for vehicle skid suppression control or an ECU for curtain airbag control.

[0058] Furthermore, acceleration detection data from acceleration sensors mounted on each of a plurality of first control devices that perform separate controls, such as the airbag control ECU, skid suppression control ECU, and curtain airbag control ECU, may be used in the optical axis control ECU 3. In this case, it is desirable that the receiving unit 31 of the optical axis control ECU 3 selectively receives acceleration detection data transmitted from the transmitting units of the plurality of first control devices. This eliminates the need for complex processing, such as receiving and processing all detection data from the plurality of acceleration sensors, even when there are a plurality of first control devices equipped with acceleration sensors (acceleration detection units). This makes it possible to prevent the optical axis control ECU 3, which is the second control device, from entering a wake-up state to receive acceleration detection data when the ignition switch is turned off, and prevents an increase in current consumption due to the wake-up of the optical axis control ECU 3.

[0059] Furthermore, in the above-described embodiment, an example was shown in which acceleration detection data from the acceleration sensor 21 was transmitted and received via CAN communication, but the present invention can also be implemented in cases in which acceleration detection data from the acceleration sensor 21 is transmitted and received via a communication method other than CAN, and it is possible to achieve effects equivalent to those of the above-described embodiment.

[0060] Furthermore, the second control device is not limited to the above-mentioned optical axis control ECU 3, and in short, the present invention can be applied to any device that performs predetermined control using acceleration detection data from the acceleration detection unit of the first control device.

[0061] Furthermore, in order to correct variations in the mounting state of the acceleration sensor 21, it is desirable to transmit information required for the variation correction in advance to the optical axis control ECU 3. Furthermore, if data before and after averaging of the acceleration detection data is transmitted to the optical axis control ECU 3, the calculation unit 32 of the optical axis control ECU 3 can perform processing to correct mounting variations of the acceleration sensor 21 based on the acceleration detection data before and after averaging.

[0062] Furthermore, in the above-described embodiment, the acceleration sensor 21 detects and stores acceleration detection data immediately before the ignition switch is turned off, and then communication is stopped when the ignition switch is turned off. However, communication may also be stopped to reduce current consumption if the acceleration sensor 21 is unable to detect acceleration detection data immediately before the ignition switch is turned off.

[0063] In addition, the first control device, such as the airbag control ECU 2, may calculate the road surface inclination angle and vehicle attitude angle based on acceleration detection data from an acceleration detection unit (acceleration sensor) and store the results in the memory 23.

[0064] The present invention can be applied to a vehicle control system that controls a vehicle based on data detected by an acceleration sensor. [Explanation of symbols]

[0065] 1. Vehicle control system 2...Airbag control ECU (first control device) 3...ECU for optical axis control (second control device) 4...Communication bus 21...Acceleration sensor (speed detection section) 23...Memory (storage section) 24...Transmitter 31...Receiver 32...Arithmetic section 33...Optical axis control section

Claims

1. A vehicle control system that controls a vehicle based on detection data from an acceleration sensor, a first control device that controls a vehicle, and a second control device that performs predetermined control of the vehicle different from the control performed by the first control device; The first control device an acceleration detection unit that detects at least vertical and longitudinal accelerations to derive a road surface inclination angle and a vehicle attitude angle; a storage unit that stores acceleration detection data from the acceleration detection unit when it is determined that the vehicle is stopped and stable; a transmitting unit that transmits the acceleration detection data stored in the storage unit immediately after an ignition switch is turned on, and transmits the acceleration detection data detected by the acceleration detection unit while the ignition switch is on; and when the ignition switch is turned off, if the acceleration detection data has been stored in the storage unit, the device goes into a sleep state, The second control device The device further includes a receiving unit that receives the acceleration detection data stored in the storage unit and transmitted from the transmitting unit immediately after the ignition switch is turned on, and receives the acceleration detection data transmitted from the transmitting unit while the ignition switch is turned on, and the acceleration detection data is not transmitted from the transmitting unit while the ignition switch is turned off. A vehicle control system comprising:

2. a plurality of the first control devices; the plurality of first control devices perform separate controls different from the predetermined control, The receiving unit of the second control device selectively receives the acceleration detection data transmitted from the transmitting units of the plurality of first control devices.

2. The vehicle control system according to claim 1.

3. The second control device a calculation unit that calculates the vehicle attitude angle based on the acceleration detection data received by the receiving unit while the ignition switch is on; an optical axis control unit that controls the tilt angle of the optical axis of the headlamp based on the vehicle attitude angle calculated by the calculation unit; 3. The vehicle control system according to claim 1, further comprising:

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